diff --git a/libmproxy/flow.py b/libmproxy/flow.py
index 6ffef6f2f..76a8a1c76 100644
--- a/libmproxy/flow.py
+++ b/libmproxy/flow.py
@@ -21,7 +21,7 @@ import hashlib, Cookie, cookielib, copy, re, urlparse
 import time
 import tnetstring, filt, script, utils, encoding, proxy
 from email.utils import parsedate_tz, formatdate, mktime_tz
-import controller, version
+import controller, version, certutils
 
 HDR_FORM_URLENCODED = "application/x-www-form-urlencoded"
 
@@ -566,12 +566,12 @@ class Response(HTTPMsg):
             content: Response content
             timestamp: Seconds since the epoch
     """
-    def __init__(self, request, code, msg, headers, content, peercert, timestamp=None):
+    def __init__(self, request, code, msg, headers, content, der_cert, timestamp=None):
         assert isinstance(headers, ODictCaseless)
         self.request = request
         self.code, self.msg = code, msg
         self.headers, self.content = headers, content
-        self.peercert = peercert
+        self.der_cert = der_cert
         self.timestamp = timestamp or utils.timestamp()
         controller.Msg.__init__(self)
         self.replay = False
@@ -641,7 +641,14 @@ class Response(HTTPMsg):
         self.headers = ODictCaseless._from_state(state["headers"])
         self.content = state["content"]
         self.timestamp = state["timestamp"]
-        self.peercert = state["peercert"]
+        self.der_cert = state["der_cert"]
+
+    def get_cert(self):
+        """
+            Returns a certutils.SSLCert object, or None.
+        """
+        if self.der_cert:
+            return certutils.SSLCert.from_der(self.der_cert)
 
     def _get_state(self):
         return dict(
@@ -649,7 +656,7 @@ class Response(HTTPMsg):
             msg = self.msg,
             headers = self.headers._get_state(),
             timestamp = self.timestamp,
-            peercert = self.peercert,
+            der_cert = self.der_cert,
             content = self.content
         )
 
@@ -661,7 +668,7 @@ class Response(HTTPMsg):
             str(state["msg"]),
             ODictCaseless._from_state(state["headers"]),
             state["content"],
-            state.get("peercert"),
+            state.get("der_cert"),
             state["timestamp"],
         )
 
diff --git a/test/test_flow.py b/test/test_flow.py
index d19518e5e..60a4fc04d 100644
--- a/test/test_flow.py
+++ b/test/test_flow.py
@@ -835,6 +835,13 @@ class uResponse(libpry.AutoTree):
         c = "MOO=BAR; Expires=Tue, 08-Mar-2011 00:20:38 GMT; Path=foo.com; Secure"
         assert "00:21:38" in r._refresh_cookie(c, 60)
 
+    def test_get_cert(self):
+        req = tutils.treq()
+        resp = flow.Response(req, 200, "msg", flow.ODictCaseless(), "content", file("data/dercert").read())
+        assert resp.get_cert()
+
+        resp = tutils.tresp()
+        assert not resp.get_cert()
 
     def test_getset_state(self):
         h = flow.ODictCaseless()